CODEWITHSUNDEEP
smartcardjavacardapdu
TheGoodUser
TheGoodUser

Reputation: 1198

Select MF (Master-File) - Read EEPROM of a javacard

I have two different javacard with below ATRs :

  1. 3B 68 00 00 00 73 C8 40 12 00 90 00
  2. 3b 7F 94 00 00 80 31 80 65 B0 85 02 02 ED 12 0F FF 82 90 00

Let assume that I want to Select MF.As far as I know, and mentioned in ISO 7815-4 , we can select Master File with 00 A4 00 00 or 00 A4 00 00 02 3F 00.

enter image description here

But when I send select MF command for the first card I receive 6A86[Incorrect parameters P1-P2].

Q1 : Does this mean MY card is not compliant with ISO-7816?! If no, what's is the reason of this error? enter image description here

And for the second card when I send SELECT MASTER FILE command and then GET RESPONSE command (00 CO OO OO 12), I receive the below output.

Q2 : What kind of information I can gain of this outut? enter image description here

Q3 : If I don't know my card file's IDs, Can I gain them with a brute brute-force on P1-P2=0000 to P1-P2=FFFF? I mean may this brute-force make my card lock?

Q4 : If I know only authentication keys of my card and nothin else, is there any way to read whole the EEPROM? if yes, how?

Thank you

Upvotes: 4

Views: 7466

Answers (2)

Maarten Bodewes
Maarten Bodewes

Reputation: 94038

A1: Your card is partially ISO 7816 compliant (like most cards out there). It will - in all likelyhood - not support SELECT MF out of the box. If required, you can make your Applet "default selected" (during INSTALL for INSTALL) - meaning that the Applet becomes selected directly after the ATR - and implement the behavior yourself.

A2: SELECT will return FCI/FCP (file control information, file control parameters) information if P2 is set to 00. What is returned again depends on the card. Sometimes it is easier to only support P2 = 0C indicating that no information is returned. This is however only available as ISO CASE 3 command, meaning that only command data is supplied (no Le byte(s)). So the 4 byte SELECT MF won't work.

A3: Yes, you can. Reading out information or selecting files does not burn through EEPROM or flash if the card is programmed correctly. Bar a EF.ATR now and then, not much files should be present on a pristine Java Card without installed Applets or native applications though. Only do this for testing purposes though, selecting all possible files during a normal read is not efficient (and some EEPROM / flash read/writes may be required for security purposes, although the OS developer should be aware of this).

A4: No, you require full card access to do that. This functionality is usually preserved to manufacturers and creators of Java Card operating systems.

Note that INITIALIZE UPDATE / EXTERNAL AUTHENTICATE is specific to the Global Platform Card Manager or Security Domains. It makes no sense to perform a SELECT MF from the Card Manager.

Upvotes: 2

Anurag Sharma
Anurag Sharma

Reputation: 502

Q1 : Does this mean MY card is not compliant with ISO-7816?! If no, what's is the reason of this error?

  • A1 : Your card is ISO 7816 compliant and selection methods are vendor specific see table 39 in ISO 7816-4
    it depends on vendor, you directly ask your vendor about supported selection methods. or you can check ATR to know which methods are supported in Table-86 in ISO 7816-4

Q2 : What kind of information I can gain of this outut?

  • A2 : This is File control parameter(FCP) which is defined in Table-12 of ISO 7816-4 see enter image description here
    it is 85 in your case.

Q3 : If I don't know my card file's IDs, Can I gain them with a brute brute-force on P1-P2=0000 to P1-P2=FFFF? I mean may this brute-force make my card lock?

  • A3 : i will not suggest this, you can simply ask your vendor about file structure present in your card, using brute-force will also decrease endurance of your card.

Q4 : If I know only authentication keys of my card and nothin else, is there any way to read whole the EEPROM? if yes, how?

  • A4 : There is no standard command to read whole EEPROM at once.

Upvotes: 4

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